Using the excess heat factor to indicate heatwave-related urinary disease: a case study in Adelaide, South Australia

The impact of extreme heat on older regional and rural Australians: A systematic review

INTRODUCTION

Extreme heat causes a major health burden, especially for older Australians.

OBJECTIVE

To assess the impact of extreme heat on older regional and rural Australians, including clinical presentations, social implications, and health-seeking behaviours and adaptations.

DESIGN

A systematic review and narrative synthesis.

FINDINGS

Ten articles were included in the review with research on this topic limited. Extreme heat causes an increase in mortality and ambulance dispatches for older rural Australians. Social connectedness is negatively affected by extreme heat due to cancellation of events and individuals becoming housebound. Air conditioning is the main cooling mechanism used, although cost is a major concern. Despite this, older rural populations display a depth of knowledge regarding practical behavioural responses to adapt to extreme heat. Studies show older rural Australians do not consider extreme heat to be a threat to health.

DISCUSSION

Further research needs to examine the role extreme heat may play in contributing to experiences of loneliness. Air conditioning cannot be the ultimate solution in responding to extreme heat due to cost and increased carbon emissions. The low-risk perception of extreme heat for older rural people may inform effective heat health warnings and effective use of primary health care in heat-health education. Listening to First Nations knowledge in dealing with heat may provide a powerful mechanism in which to protect health.

CONCLUSION

The extensive health effects of extreme heat highlights the necessity of further research and strengthening of services in preparation for an ageing rural population enduring climate change.

Impact of heat on emergency hospital admissions related to kidney diseases in Texas: Uncovering racial disparities

BACKGROUND AND OBJECTIVE

While impact of heat exposure on human health is well-documented, limited research exists on its effect on kidney disease hospital admissions especially in Texas, a state with diverse demographics and a high heat-related death rate. We aimed to explore the link between high temperatures and emergency kidney disease hospital admissions across 12 Texas Metropolitan Statistical Areas (MSAs) from 2004 to 2013, considering causes, age groups, and ethnic populations.

METHODS

To investigate the correlation between high temperatures and emergency hospital admissions, we utilized MSA-level hospital admission and weather data. We employed a Generalized Additive Model to calculate the association specific to each MSA, and then performed a random effects meta-analysis to estimate the overall correlation. Analyses were stratified by age groups, admission causes, and racial/ethnic disparities. Sensitivity analysis involved lag modifications and ozone inclusion in the model.

RESULTS

Our analysis found that each 1 °C increase in temperature was associated with a 1.73 % (95 % CI [1.43, 2.03]) increase in hospital admissions related to all types of kidney diseases. Besides, the effect estimates varied across different age groups and specific types of kidney diseases. We observed statistically significant associations between high temperatures and emergency hospital admissions for Acute Kidney Injury (AKI) (3.34 % (95 % CI [2.86, 3.82])), Kidney Stone (1.76 % (95 % CI [0.94, 2.60])), and Urinary Tract Infections (UTI) (1.06 % (95 % CI [0.61, 1.51])). Our research findings indicate disparities in certain Metropolitan Statistical Areas (MSAs). In Austin, Houston, San Antonio, and Dallas metropolitan areas, the estimated effects are more pronounced for African Americans when compared to the White population. Additionally, in Dallas, Houston, El Paso, and San Antonio, the estimated effects are greater for the Hispanic group compared to the Non-Hispanic group.

CONCLUSIONS

This study finds a strong link between higher temperatures and kidney disease-related hospital admissions in Texas, especially for AKI. Public health actions are necessary to address these temperature-related health risks, including targeted kidney health initiatives. More research is needed to understand the mechanisms and address health disparities among racial/ethnic groups.

Current and projected heatwave-attributable occupational injuries, illnesses, and associated economic burden in Australia

INTRODUCTION

The costs of global warming are substantial. These include expenses from occupational illnesses and injuries (OIIs), which have been associated with increases during heatwaves. This study estimated retrospective and projected future heatwave-attributable OIIs and their costs in Australia.

MATERIALS AND METHODS

Climate and workers' compensation claims data were extracted from seven Australian capital cities representing OIIs from July 2005 to June 2018. Heatwaves were defined using the Excess Heat Factor. OIIs and associated costs were estimated separately per city and pooled to derive national estimates. Results were projected to 2030 (2016-2045) and 2050 (2036-2065).

RESULTS

The risk of OIIs and associated costs increased during heatwaves, with the risk increasing during severe and particularly extreme heatwaves. Of all OIIs, 0.13% (95% empirical confidence interval [eCI]: 0.11-0.16%) were heatwave-attributable, equivalent to 120 (95%eCI:70-181) OIIs annually. 0.25% of costs were heatwave-attributable (95%eCI: 0.18-0.34%), equal to $AU4.3 (95%eCI: 1.4-7.4) million annually. Estimates of heatwave-attributable OIIs by 2050, under Representative Concentration Pathway [RCP]4.5 and RCP8.5, were 0.17% (95%eCI: 0.10-0.27%) and 0.23% (95%eCI: 0.13-0.37%), respectively. National costs estimates for 2030 under RCP4.5 and RCP8.5 were 0.13% (95%eCI: 0.27-0.46%) and 0.04% (95%eCI: 0.66-0.60), respectively. These estimates for extreme heatwaves were 0.04% (95%eCI: 0.02-0.06%) and 0.04% (95%eCI: 0.01-0.07), respectively. Cost-AFs in 2050 were, under RCP4.5, 0.127% (95%eCI: 0.27-0.46) for all heatwaves and 0.04% (95%eCI: 0.01-0.09%) for extreme heatwaves. Attributable fractions were approximately similar to baseline when assuming theoretical climate adaptation.

DISCUSSION

Heatwaves represent notable and preventable portions of preventable OIIs and economic burden. OIIs are likely to increase in the future, and costs during extreme heatwaves in 2030. Workplace and public health policies aimed at heat adaptation can reduce heat-attributable morbidity and costs.

Environmental heat exposure and implications on renal health of pediatric communities in the dry climatic zone of Sri Lanka: An approach with urinary biomarkers

Prolonged heat exposure during outdoor physical exertion can result in adverse renal health outcomes, and it is also supposed to be a driver of chronic kidney disease of uncertain etiology (CKDu) in tropical regions. School students are more likely to experience high heat exposure during outdoor sports practices, and the current knowledge on potential renal health outcomes associated with heat exposure carries many knowledge gaps. Hence, the present study aimed to perform biomarker-based assessment of the likelihood of pediatric renal injury focusing the communities in the dry climatic zone in Sri Lanka, where it prevails relatively harsh climate and high prevalence of CKDu. School students who engaged in regular outdoor sports practices (high-heat exposure), and an age-matched control of students who did not engage in sports practices (low-heat exposure) from four educational zones: Padavi Sripura (N = 159) and Medirigiriya (N = 171), Uhana (N = 165) and Thanamalwila (N = 169) participated in this cross-sectional study representing CKDu endemic and non-endemic regions. Effective temperature (ET), wet-bulb globe temperature (WBGT), heat index (HI) and humidex were used for comparison of thermal comfort in the environment. The intensity of environmental heat measured by thermal comfort indices showed no significant difference (p > 0.05) among the study regions. Urinary kidney injury molecule (KIM-1) and albumin-creatinine ratio (ACR) in participants with high heat exposure did not differ significantly from those in the control groups in the four study zones, where urinary neutrophil gelatinase-associated lipocalin showed substantial differences in some groups. Irrespective of heat exposure, increased KIM-1 excretion was observed (p < 0.01) in participants of CKDu endemic regions compared to those in non-endemic areas. Within the context of our findings, there is no plausibly strong evidence to establish potential association of heat exposure with the likelihood of developing renal injury or abnormal renal outcomes in dry zone school students in Sri Lanka.

"Failing kidneys in a failing planet; CKD of unknown origin"

The 'alarm clock' for human beings in the era of climate medicine has rung. Original diseases have appeared, that could not be explained and attributed to common causes, which are suggested to be linked to global warming and environmental factors. Such an indolent disease is the chronic kidney disease of unknown cause (CKDu), introduced also as Mesoamerican or Uddanam nephropathy. Scientists equate the climate impact on kidneys with the canary in the coal mine; coal miners used to carry caged canaries with them, so that if poisonous gases, such as methane or carbon monoxide leaked into the mine-shaft, the gases would kill the canary before killing the miners; similarly, kidneys are injured before devastating and lethal complications occur in humans. In some regions of Central America, the deaths due to chronic kidney disease increased by 177% with a death toll being as high as over 20,000. It was first documented in animals that periodic heat and dehydration have a major role in causing chronic kidney disease. Based on that observation, it is advocated that young male agricultural workers in Central America and South Asia, develop renal disease by getting exposed to extreme heat repeatedly. The clinico-pathological characteristics of this type of kidney injury, do not belong to an existing classification, even though a form of tubulo-interstitial renal disease has been proposed. In this review, we will discuss about CKDu, its epidemiology and pathophysiological mechanisms, clinical presentation and diagnostic biomarkers and examine potential therapeutic options.

Determining the Impact of Heatwaves on Emergency Ambulance Calls in Queensland: A Retrospective Population-Based Study

Heatwaves are a significant and growing threat to the health and well-being of the residents of Queensland, Australia. This threat is increasing due to climate change. Excess heat increases the demand for health services, including ambulance calls, and the purpose of this study was to explore this impact across Queensland. A state-wide retrospective analysis of heatwaves and emergency 'Triple Zero' (000) calls to Queensland Ambulance (QAS) from 2010-2019 was undertaken. Call data from the QAS and heatwave data from the Bureau of Meteorology were analysed using a case-crossover approach at the postcode level. Ambulance calls increased by 12.68% during heatwaves. The effect was greatest during low-severity heatwaves (22.16%), followed by severe (14.32%) and extreme heatwaves (1.16%). The impact varied by rurality, with those living in very remote areas and major cities most impacted, along with those of low and middle socioeconomic status during low and severe intensity heat events. Lag effects post-heatwave continued for at least 10 days. Heatwaves significantly increase ambulance call centre workload, so ambulance services must actively prepare resources and personnel to address increases in heatwave frequency, duration, and severity. Communities must be informed of the risks of heatwaves at all severities, particularly low severity, and the sustained risks in the days following a heat event.

Associations between short-term temperature exposure and kidney-related conditions in New York State: The influence of temperature metrics across four dimensions

BACKGROUND

Evidence describing the relationship between short-term temperature exposure and kidney-related conditions is insufficient. It remains unclear how temperature specification affects estimation of these associations. This study aimed to assess associations between short-term temperature exposure and seven kidney-related conditions and to evaluate the influence of temperature specification.

METHODS

We obtained data on hospital encounters in New York State (2007-2016). We assessed associations with a case-crossover design using conditional logistic regression with distributed lag non-linear models. We compared model performance (i.e., AIC) and association curves using 1) five temperature spatial resolutions; 2) temperature on an absolute versus relative scale; 3) seven temperature metrics incorporating humidity, wind speed, and/or solar radiation; and 4) five intraday temperature measures (e.g., daily minimum and daytime mean).

RESULTS

We included 1,209,934 unplanned adult encounters. Temperature metric and intraday measure had considerably greater influence than spatial resolution and temperature scale. For outcomes not associated with temperature exposure, almost all metrics or intraday measures showed good model performance; for outcomes associated with temperature, there were meaningful differences in performance across metrics or intraday measures. For parsimony, we modelled daytime mean outdoor wet-bulb globe temperature, which showed good performance for all outcomes. At lag 0-6 days, we observed increased risk at the 95^th percentile of temperature versus the minimum morbidity temperature for acute kidney failure (odds ratio [OR] = 1.36, 95% confidence interval [CI]: 1.09, 1.69), urolithiasis (OR = 1.41, 95% CI: 1.16, 1.70), dysnatremia (OR = 1.26, 95% CI: 1.01, 1.59), and volume depletion (OR = 1.88, 95% CI: 1.41, 2.51), but not for glomerular diseases, renal tubulo-interstitial diseases, and chronic kidney disease.

CONCLUSIONS

High-temperature exposure over one week is a risk factor for acute kidney failure, urolithiasis, dysnatremia, and volume depletion. The differential model performance across temperature metrics and intraday measures indicates the importance of careful selection of exposure metrics when estimating temperature-related health burden.

Heatwave and urinary hospital admissions in China: Disease burden and associated economic loss, 2014 to 2019

BACKGROUND

Many studies have shown that heatwaves are associated with an increased prevalence of urinary diseases. However, few national studies have been undertaken in China, and none have considered the associated economic losses. Such information would be useful for health authorities and medical service providers to improve their policy-making and medical resource allocation decisions.

OBJECTIVES

To explore the association between heatwaves and hospital admissions for urinary diseases and assess the related medical costs and indirect economic losses in China from 2014 to 2019.

METHODS

Daily meteorological and hospital admission data from 2014 to 2019 were collected from 23 study sites with different climatic characteristics in China. We assessed the heatwave-hospitalization associations and evaluated the location-specific attributable fractions (AFs) of urinary-related hospital admissions due to heatwaves by using a time-stratified case-crossover method with a distributed lag nonlinear model. We then pooled the AFs in a meta-analysis and estimated the national excess disease burden and associated economic losses. We also performed stratified analyses by sex, age, climate zone, and urinary disease subtype.

RESULTS

A significant association between heatwaves and urinary-related hospital admissions was found with a relative risk of 1.090 (95 % confidence interval (CI): 1.050, 1.132). The pooled AF was 8.27 % (95%CI: 4.77 %, 11.63 %), indicating that heatwaves during the warm season (May to September) caused 248,364 urinary-related hospital admissions per year, with 2.42 (95%CI: 1.35, 3.45) billion CNY in economic losses, including 2.23 (95%CI: 1.29, 3.14) billion in direct losses and 0.19 (95%CI, 0.06, 0.31) billion in indirect losses, males, people aged 15-64 years, residents of temperate continental climate zones, and patients with urolithiasis were at higher risk.

CONCLUSION

Tailored community health campaigns should be developed and implemented to reduce the adverse health effects and economic losses of heatwave-related urinary diseases, especially in the context of climate change.

Adverse heat-health outcomes and critical environmental limits (Pennsylvania State University Human Environmental Age Thresholds project)

BACKGROUND

The earth's climate is warming and the frequency, duration, and severity of heat waves are increasing. Meanwhile, the world's population is rapidly aging. Epidemiological data demonstrate exponentially greater increases in morbidity and mortality during heat waves in adults ≥65 years. Laboratory data substantiate the mechanistic underpinnings of age-associated differences in thermoregulatory function. However, the specific combinations of environmental conditions (i.e., ambient temperature and absolute/relative humidity) above which older adults are at increased risk of heat-related morbidity and mortality are less clear.

METHODS

This review was conducted to (1) examine the recent (past 3 years) literature regarding heat-related morbidity and mortality in the elderly and discuss projections of future heat-related morbidity and mortality based on climate model data, and (2) detail the background and unique methodology of our ongoing laboratory-based projects aimed toward identifying the specific environmental conditions that result in elevated risk of heat illness in older adults, and the implications of using the data toward the development of evidence-based safety interventions in a continually-warming climate (PSU HEAT; Human Environmental Age Thresholds).

RESULTS

The recent literature demonstrates that extreme heat continues to be increasingly detrimental to the health of the elderly and that this is apparent across the world, although the specific environmental conditions above which older adults are at increased risk of heat-related morbidity and mortality remain unclear.

CONCLUSION

Characterizing the environmental conditions above which risk of heat-related illnesses increase remains critical to enact policy decisions and mitigation efforts to protect vulnerable people during extreme heat events.

The Impact of Heatwaves on Mortality and Morbidity and the Associated Vulnerability Factors: A Systematic Review

BACKGROUND

This study aims to investigate the current impacts of extreme temperature and heatwaves on human health in terms of both mortality and morbidity. This systematic review analyzed the impact of heatwaves on mortality, morbidity, and the associated vulnerability factors, focusing on the sensitivity component.

METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 flow checklist. Four databases (Scopus, Web of Science, EBSCOhost, PubMed) were searched for articles published from 2012 to 2022. Those eligible were evaluated using the Navigation Guide Systematic Review framework.

RESULTS

A total of 32 articles were included in the systematic review. Heatwave events increased mortality and morbidity incidence. Sociodemographic (elderly, children, male, female, low socioeconomic, low education), medical conditions (cardiopulmonary diseases, renal disease, diabetes, mental disease), and rural areas were crucial vulnerability factors.

CONCLUSIONS

While mortality and morbidity are critical aspects for measuring the impact of heatwaves on human health, the sensitivity in the context of sociodemographic, medical conditions, and locality posed a higher vulnerability to certain groups. Therefore, further research on climate change and health impacts on vulnerability may help stakeholders strategize effective plans to reduce the effect of heatwaves.

Association of summer temperatures and acute kidney injury in South Korea: a case-crossover study

BACKGROUND

Due to climate change, days with high temperatures are becoming more frequent. Although the effect of high temperature on the kidneys has been reported in research from Central and South America, Oceania, North America and Europe, evidence from Asia is still lacking. This study aimed to examine the association between short-term exposure to high temperatures and acute kidney injury (AKI) in a nationwide study in South Korea.

METHODS

We used representative sampling data from the 2002-2015 National Health Insurance Service-National Sample Cohort in South Korea to link the daily mean temperatures and AKI cases that occurred in the summer. We used a bidirectional case-crossover study design with 0-7 lag days before the emergency room visit for AKI. In addition, we stratified the data into six income levels to identify the susceptible population.

RESULTS

A total of 1706 participants were included in this study. The odds ratio (OR) per 1°C increase at 0 lag days was 1.051, and the ORs per 1°C increase at a lag of 2 days were both 1.076. The association between exposure to high temperatures and AKI was slightly greater in the low-income group (OR = 1.088; 95% CI: 1.049-1.128) than in the high-income group (OR = 1.065; 95% CI: 1.026-1.105).

CONCLUSIONS

In our study, a relationship between exposure to high temperatures and AKI was observed. Precautions should be taken at elevated temperatures to minimize the risk of negative health effects.

Systematic review of the impact of heatwaves on health service demand in Australia

OBJECTIVES

Heatwaves have been linked to increased levels of health service demand in Australia. This systematic literature review aimed to explore health service demand during Australian heatwaves for hospital admissions, emergency department presentations, ambulance call-outs, and risk of mortality.

STUDY DESIGN

A systematic review to explore peer-reviewed heatwave literature published from 2000 to 2020.

DATA SOURCES

Articles were reviewed from six databases (MEDLINE, Scopus, Web of Science, PsychINFO, ProQuest, Science Direct). Search terms included: heatwave, extreme heat, ambulance, emergency department, and hospital. Studies were included if they explored heat for a period of two or more consecutive days. Studies were excluded if they did not define a threshold for extreme heat or if they explored data only from workers compensation claims and major events.

DATA SYNTHESIS

This review was prospectively registered with PROSPERO (# CRD42021227395 ). Forty-five papers were included in the final review following full-text screening. Following a quality assessment using the GRADE approach, data were extracted to a spreadsheet and compared. Significant increases in mortality, as well as hospital, emergency, and ambulance demand, were found across Australia during heatwave periods. Admissions for cardiovascular, renal, respiratory, mental and behavioural conditions exhibited increases during heatwaves. The most vulnerable groups during heatwaves were children (< 18 years) and the elderly (60+).

CONCLUSIONS

Heatwaves in Australia will continue to increase in duration and frequency due to the effects of climate change. Health planning is essential at the community, state, and federal levels to mitigate the impacts of heatwaves on health and health service delivery especially for vulnerable populations. However, understanding the true impact of heatwaves on health service demand is complicated by differing definitions and methodology in the literature. The Excess Heat Factor (EHF) is the preferred approach to defining heatwaves given its consideration of local climate variability and acclimatisation. Future research should explore evidence-based and spatially relevant heatwave prevention programs. An enhanced understanding of heatwave health impacts including service demand will inform the development of such programs which are necessary to promote population and health system resilience.

Estimating Heat-Related Exposures and Urban Heat Island Impacts: A Case Study for the 2012 Chicago Heatwave

Accelerated urbanization increases both the frequency and intensity of heatwaves (HW) and urban heat islands (UHIs). An extreme HW event occurred in 2012 summer that caused temperatures of more than 40°C in Chicago, Illinois, USA, which is a highly urbanized city impacted by UHIs. In this study, multiple numerical models, including the High Resolution Land Data Assimilation System (HRLDAS) and Weather Research and Forecasting (WRF) model, were used to simulate the HW and UHI, and their performance was evaluated. In addition, sensitivity testing of three different WRF configurations was done to determine the impact of increasing model complexity in simulating urban meteorology. Model performances were evaluated based on the statistical performance metrics, the application of a multi-layer urban canopy model (MLUCM) helps WRF to provide the best performance in this study. HW caused rural temperatures to increase by ∼4°C, whereas urban Chicago had lower magnitude increases from the HW (∼2-3°C increases). Nighttime UHI intensity (UHII) ranged from 1.44 to 2.83°C during the study period. Spatiotemporal temperature fields were used to estimate the potential heat-related exposure and to quantify the Excessive Heat Factor (EHF). The EHF during the HW episode provides a risk map indicating that while urban Chicago had higher heat-related stress during this event, the rural area also had high risk, especially during nighttime in central Illinois. This study provides a reliable method to estimate spatiotemporal exposures for future studies of heat-related health impacts.

Hot weather as a risk factor for kidney disease outcomes: A systematic review and meta-analysis of epidemiological evidence

BACKGROUND

The occurrence or exacerbation of kidney disease has been documented as a growing problem associated with hot weather. The implementation of effective prevention measures requires a better understanding of the risk factors that increase susceptibility. To fill gaps in knowledge, this study reviews the current literature on the effects of heat on kidney-disease outcomes (ICD-10 N00-N39), including morbidity and mortality.

METHODS

Databases were systematically searched for relevant literature published between 1990 and 2020 and the quality of evidence evaluated. We performed random effects meta-analysis to calculate the pooled relative risks (RRs) of the association between high temperatures (and heatwaves) and kidney disease outcomes. We further evaluated vulnerability concerning contextual population characteristics.

RESULTS

Of 2739 studies identified, 91 were reviewed and 82 of these studies met the criteria for inclusion in a meta-analysis. Findings showed that with a 1 °C increase in temperature, the risk of kidney-related morbidity increased by 1% (RR 1.010; 95% CI: 1.009-1.011), with the greatest risk for urolithiasis. Heatwaves were also associated with increased morbidity with a trend observed with heatwave intensity. During low-intensity heatwaves, there was an increase of 5.9% in morbidity, while during high-intensity heatwaves there was a 7.7% increase. There were greater RRs for males, people aged ≤64 years, and those living in temperate climate zones. Similarly, for every 1 °C temperature increase, there was a 3% (RR 1.031; 95% CI: 1.018-1.045) increase in the risk of kidney-related mortality, which also increased during heatwaves.

CONCLUSIONS

High temperatures (and heatwaves) are associated with an elevated risk of kidney disease outcomes, particularly urolithiasis. Preventive measures that may minimize risks in vulnerable individuals during hot spells are discussed.

Acute associations between heatwaves and preterm and early-term birth in 50 US metropolitan areas: a matched case-control study

BACKGROUND

The effect of heatwaves on adverse birth outcomes is not well understood and may vary by how heatwaves are defined. The study aims to examine acute associations between various heatwave definitions and preterm and early-term birth.

METHODS

Using national vital records from 50 metropolitan statistical areas (MSAs) between 1982 and 1988, singleton preterm (< 37 weeks) and early-term births (37-38 weeks) were matched (1:1) to controls who completed at least 37 weeks or 39 weeks of gestation, respectively. Matching variables were MSA, maternal race, and maternal education. Sixty heatwave definitions including binary indicators for exposure to sustained heat, number of high heat days, and measures of heat intensity (the average degrees over the threshold in the past 7 days) based on the 97.5th percentile of MSA-specific temperature metrics, or the 85th percentile of positive excessive heat factor (EHF) were created. Odds ratios (OR) for heatwave exposures in the week preceding birth (or corresponding gestational week for controls) were estimated using conditional logistic regression adjusting for maternal age, marital status, and seasonality. Effect modification by maternal education, age, race/ethnicity, child sex, and region was assessed.

RESULTS

There were 615,329 preterm and 1,005,576 early-term case-control pairs in the analyses. For most definitions, exposure to heatwaves in the week before delivery was consistently associated with increased odds of early-term birth. Exposure to more high heat days and more degrees above the threshold yielded higher magnitude ORs. For exposure to 3 or more days over the 97.5th percentile of mean temperature in the past week compared to zero days, the OR was 1.027 for early-term birth (95%CI: 1.014, 1.039). Although we generally found null associations when assessing various heatwave definitions and preterm birth, ORs for both preterm and early-term birth were greater in magnitude among Hispanic and non-Hispanic black mothers.

CONCLUSION

Although associations varied across metrics and heatwave definitions, heatwaves were more consistently associated with early-term birth than with preterm birth. This study's findings may have implications for prevention programs targeting vulnerable subgroups as climate change progresses.

High temperatures and emergency department visits in 18 sites with different climatic characteristics in China: Risk assessment and attributable fraction identification

BACKGROUND

Health impacts of high temperatures on hospital emergency department visits (EDVs) have been less reported, especially from developing countries.

OBJECTIVES

To investigate high temperature-EDVs relationship in various regions with different climatic characteristics, to explore the regional differences, to identify vulnerable populations, and to provide scientific evidence for climate change adaptation strategies in China.

METHODS

Daily data on weather, air pollution and EDVs were collected from 18 sites in China from June to August during 2014-2017. A quasi-Poisson generalized additive regression model was applied to examine the high temperature-EDVs relationship in each site. Site-specific risks of EDVs were pooled using a random effect meta-analysis model. Stratified analyses were performed by gender, age-groups, cause-specific EDVs and regions. Attributable fractions of EDVs due to high temperatures were calculated in different regions.

RESULTS

1 °C increase in daily mean temperature was associated with 1.07% (95% CI, 0.46-1.67%) increase in EDVs across all study regions. The negative health effects from high temperatures were worse for the people living in southern China, in subtropical monsoon climate zone or in counties, with percentage change of 1.96% (95% CI, 0.92-3.02%), 1.35% (95% CI, 0.95-1.76%) and 1.41% (95% CI, 0.48-2.34%), respectively. People under 18 were more vulnerable to high temperatures. Exposure to high temperatures increased EDVs risks from endocrine, respiratory, and digestive diseases and injury. The attributable fraction due to high temperatures was 8.64% for overall EDVs, 11.70% for the people living in southern China, 10.80% for people living in subtropical monsoon climate zone and 12.65% for the county population.

CONCLUSIONS

Exposure to high temperatures resulted in extra burden to China's already overloaded hospital emergency departments. More resources are needed to meet increasing demands and effective preventative measurements are warranted to tackle such a challenge. Further studies should pay more attention to both heat and cold-related EDVs risks and socioeconomic cost for better climate change adaptation.

Renal and segmental artery hemodynamics during whole body passive heating and cooling recovery

High environmental temperatures are associated with increased risk of acute kidney injury, which may be related to reductions in renal blood flow. The susceptibility of the kidneys may be increased because of heat stress-induced changes in renal vascular resistance (RVR) to sympathetic activation. We tested the hypotheses that, compared with normothermia, increases in RVR during the cold pressor test (CPT, a sympathoexcitatory maneuver) are attenuated during passive heating and exacerbated after cooling recovery. Twenty-four healthy adults (22 ± 2 yr; 12 women, 12 men) completed CPTs at normothermic baseline, after passive heating to a rise in core temperature of ~1.2°C, and after cooling recovery when core temperature returned to ~0.2°C above normothermic baseline. Blood velocity was measured by Doppler ultrasound in the distal segment of the right renal artery (Renal, n = 24 during thermal stress, n = 12 during CPTs) or the middle portion of a segmental artery (Segmental, n = 12). RVR was calculated as mean arterial pressure divided by renal or segmental blood velocity. RVR increased at the end of CPT during normothermic baseline in both arteries (Renal: by 1.0 ± 1.0 mmHg·cm−1·s, Segmental: by 2.2 ± 1.2 mmHg·cm−1·s, P ≤ 0.03), and these increases were abolished with passive heating ( P ≥ 0.76). At the end of cooling recovery, RVR in both arteries to the CPT was restored to that of normothermic baseline ( P ≤ 0.17). These data show that increases in RVR to sympathetic activation during passive heating are attenuated and return to that of normothermic baseline after cooling recovery.

NEW & NOTEWORTHY Our data indicate that increases in renal vascular resistance to the cold pressor test (i.e., sympathetic activation) are attenuated during passive heating, but at the end of cooling recovery this response returns to that of normothermic baseline. Importantly, hemodynamic responses were assessed in arteries going to (renal artery) and within (segmental artery) the kidney, which has not been previously examined in the same study during thermal and/or sympathetic stressors.

Response of Urban Heat Stress to Heat Waves in Athens (1960–2017)

The increasing frequency, intensity and duration of heat waves seem to follow the observed global warming in recent decades. Vulnerability to heat waves is expected to increase in urban environments mainly due to population density and the effect of the urban heat island that make cities hotter than surrounding non-urban areas. The present study focuses on a vulnerable area of the eastern Mediterranean, already characterized as a ‘hot spot’ with respect to heat-related risk and investigates the change in heat stress levels during heat wave compared to non-heat wave conditions as well as the way that heat stress levels respond to heat waves in urban, compared to non-urban, environments. The adoption of a metric accounting for both the intensity and duration of the hot event yielded a total of 46 heat wave episodes over a nearly 60-year period, but with very rare occurrence until the late 1990s and a profound increased frequency thereafter. The results reveal a difference of at least one thermal stress category between heat wave and non-heat wave periods, which is apparent across the entire range of the thermal stress distribution. The analysis demonstrates a robust intensification of nighttime heat stress conditions in urban, compared to non-urban, sites during severe heat waves. Nevertheless, severe heat waves almost equalize heat stress conditions between urban and non-urban sites during midday.

Temperature as a risk factor of emergency department visits for acute kidney injury: a case-crossover study in Seoul, South Korea

BACKGROUND

Previous studies show that escalations in ambient temperature are among the risk factors for acute kidney injury (AKI). However, it has not been adequately studied in our location, Seoul, South Korea. In this study, we aimed to examine the association between ambient temperatures and AKI morbidity using emergency department (ED) visit data.

METHODS

We obtained data on ED visits from the National Emergency Medical Center for 21,656 reported cases of AKI from 2010 to 2014. Time-stratified case-crossover design analysis based on conditional logistic regression was used to analyze short-term effects of ambient temperature on AKI after controlling for relevant covariates. The shape of the exposure-response curve, effect modification by individual demographic characteristics, season, and comorbidities, as well as lag effects, were investigated.

RESULTS

The odds ratio (OR) per 1 °C increase at lag 0 was 1.0087 (95% confidence interval [CI]: 1.0041-1.0134). Risks were higher during the warm season (OR = 1.0149; 95% CI: 1.0065-1.0234) than during the cool season (OR = 1.0059; 95% CI: 1.0003-1.0116) and even higher above 22.3 °C (OR = 1.0235; 95% CI: 1.0230-1.0239).

CONCLUSIONS

This study provides evidence that ED visits for AKI were associated with ambient temperature. Early detection and treatment of patients at risk is important in both clinical and economic concerns related to AKI.